Therefore, its known narrative elements are not a part of the Doctor Who universe as we, on this Wiki, choose to define it. It may have been the basis for a similar story in another medium, however — and that story may indeed be valid.
The Giants was an unproduced story for the First Doctor mentioned in the second "Dr. Who" memo. The first 2 episodes were written by C. E. Webber before the script was dropped and replaced with Anthony Coburn's The Tribe of Gum, later known as An Unearthly Child. The first of Webber's scripts was incorporated into this new serial.
The scripts for both episodes of this serial are now considered lost. (DWM 467)